I’ve always believed that the health care debate should be based on evidence, not ideology or demagoguery. Last week, the debate gained important new evidence thanks to an unprecedented study from Oregon.In 2008, Oregon policymakers wanted to expand the state’s Medicaid program, but they lacked the funding needed to cover all 90,000 applicants. They decided that the fairest way to distribute their limited funds was through a lottery.

When researchers compared the 10,000 individuals who “won” the health care lottery to those who lost, they found dramatic differences in outcomes between these well-matched populations. Individuals covered by Medicaid were 35 percent more likely to see a doctor. They also felt better: they were more likely to rate their health as good or excellent and less likely to say that their health had deteriorated over the previous year.

Would you be surprised to learn that insurance coverage improved not only people’s physical health but also their financial well-being? People covered by Medicaid were 25 percent less likely to have an unpaid bill go to collection, and they were 40 percent less likely to borrow money or skip a bill payment because of medical expenses.

Although Oregon’s method of handling its budget limitations was novel, it dramatized an everyday phenomenon: a health care “lottery” in which some people gain health coverage while others are left to fend for themselves. Two similar Americans who work equally hard and are equally deserving of good health may experience very different outcomes, based only on chance factors: whether they live in a city with a strong job market, whether their employer provides health insurance, or whether their state supports its low-income workers through Medicaid.

Right now, 50 million Americans – including 8 million children – are losing the health care lottery. They are suffering all of the ills that the Oregon study revealed: poorer health, poorer access to doctors, and poorer financial security.

That situation is improving as the new Affordable Care law takes effect and helps 33 million Americans gain access to health insurance. Policymakers now have hard evidence to support what many of us argued when we enacted that law: insured Americans live healthier, happier, and more secure lives.